.yin{display: none;}
.xian{display: block;}

#all{width:600px;margin:0 auto;}
#top{
    border:1px solid red;
    height: 60px;}
#top img{
    display: block;
    height: 40px;
    /*logo的定位一般都是绝对定位.*/
    position: absolute;
    margin:10px 0 0 460px ;
}
#top div{

    width: 150px;
    height: 45px;
    line-height: 45px;
    text-align:center;
    background:gray;
}
/*第一个DIV的位置调整*/
#top div:nth-child(2){
    margin:15px 0 0 20px ;
}
/*第二个DIV的位置调整*/
#top div:nth-child(3){
    margin:-45px 0 0 180px ;
}

/**将span设置成按钮手势*/
#ipt1,#ipt2{cursor: pointer;}



#mid{
    height: 230px;
}

#mid ul li{
    padding-left: 20px;
    padding-top: 20px;
}
#mid div:nth-child(1),#mid div:nth-child(2){
    height: 180px;
}

#mid div:nth-child(1){
    background: lightblue;
}
#mid div:nth-child(2){
    background: lightpink;
}


#mid div:nth-child(3){
    border:1px solid red;
    height: 50px;
}

#mid #but2{
    /**使用内边距会撑开盒子*/
    border:none;
    padding:0 0 0 16px ;
    background: url("../image/bg1.png") no-repeat;
    float: right;
}

#mid #but1{
    width: 150px;
    height: 50px;
    line-height: 45px;
    font-size:25px;
    text-align:center;
    background:green;
}
#bot{
    border:1px solid blue;
    height: 180px;
}
#bot div:nth-child(1),#bot div:nth-child(2){
    height: 180px;
}

#bot div:nth-child(1){
    background: rosybrown;
}
#bot div:nth-child(2){
    background: rebeccapurple;
}
#bot ul li{
    padding-left: 20px;
    padding-top: 20px;
}